<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script type="text/javascript">
			// 把变的数据作为参数传递过来
			// calculate  
			// type: + - * /
			// cal('+');   cal('-');
		    // var type = '+';
			function cal(type) {
				console.log(type);
				var n = num1.value;
				var num2 = document.getElementById("num2").value;
				var result;
				switch (type) {
					case '+':
					  result = parseInt(num1) + parseInt(num2);
					break;
					case '-':
					  result = parseInt(num1) - parseInt(num2);
					break;
					case '*':
					  result = parseInt(num1) * parseInt(num2);
					break;
					case '/':
					  result = parseInt(num1) / parseInt(num2);
					break;
				}
				var resultInput = document.getElementById('result');
				resultInput.value = result;
			}
			
			function add() {
				var num1 = document.getElementById("num1").value;
				var num2 = document.getElementById("num2").value;
				var result = parseInt(num1) + parseInt(num2);
				var resultInput = document.getElementById('result');
				resultInput.value = result;
			}
			
			function sub() {
				var num1 = document.getElementById("num1").value;
				var num2 = document.getElementById("num2").value;
				var result = parseInt(num1) - parseInt(num2);
				var resultInput = document.getElementById('result');
				resultInput.value = result;
			}
			
			function mul() {
				var num1 = document.getElementById("num1").value;
				var num2 = document.getElementById("num2").value;
				var result = parseInt(num1) * parseInt(num2);
				var resultInput = document.getElementById('result');
				resultInput.value = result;
			}
			
			function div() {
				var num1 = document.getElementById("num1").value;
				var num2 = document.getElementById("num2").value;
				var result = parseInt(num1) / parseInt(num2);
				var resultInput = document.getElementById('result');
				resultInput.value = result;
			}
		</script>
	</head>
	<body>
		<table>
			<tr>
				<td><img src="shop.jpg" /></td>
				<td colSpan="3">购物简易计算器</td>
			</tr>
			<tr>
				<td>第一个数</td>
				<td colSpan="3">
					<input type="text" id="num1" />
				</td>
			</tr>
			<tr>
				<td>第二个数</td>
				<td colSpan="3">
					<input type="text" id="num2" />
				</td>
			</tr>
			<tr>
				<td>
					<input type="button" value=" + " onclick="cal('+')" />
				</td>
				<td>
					<input type="button" value=" - " onclick="cal('-')" />
				</td>
				<td>
					<input type="button" value=" * " onclick="cal('*')" />
				</td>
				<td>
					<input type="button" value=" / " onclick="cal('/')" />
				</td>
			</tr>
			<tr>
				<td>计算结果</td>
				<td colSpan="3">
					<input type="text" id="result" />
				</td>
			</tr>
		</table>
	</body>
</html>
